NVIDIA 670s/680s versus AMD Radeon 6970s

Hi everyone, I'm getting ready for this month's batch of upcoming games and was writing to inquire which combination of cards would you recommend for my upcoming rig in terms of price and performance.

I've personally been a NVIDIA person for quite some time, but I've been divided when I was provided the offer of 2 AMD Radeon 7970 cards for $350, which is $50 less than the NVIDIA 670s that are supposed to come out Sunday and $150 less than the 680s, which are currently in limited stock. My concern here is the 7970s are definitely trumped by the 680s, and there could be a potential price drop in the future with the introduction of the 670s. Additionally, a newer set of 7970s are going to come out with a higher clock rate of 1 GHz.

I'm planning on running dual SLI or CrossfireX on an otherwise economical rig of an i7-3770K with an ASUS Deluxe Z77 mobo, dual monitor 3920x1080 resolution.

Question I have is for the value (quality versus price), what does everyone think is better?

AMD Radeon 7970 CrossfireX at $350 each
NVIDIA 670s Dual-SLI at $400 each (probably)
NVIDIA 680s Dual SLI at $500 each
or NVIDIA 690 at $1000

On a sheer value standpoint, I'm leaning towards the first two, but the enthusiast part of me wants the 680s. I'm sure there are also more subtle aspects worth considering like heat generation and power consumption although they might be minor players in the consumption.

What does everyone else think? Personally, I don't have as much experience with AMD cards as I do with NVIDIA, so I can't testify as much regarding the quality of the cards and CrossfireX.

Thanks everyone for the feedback in advance!